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Abstract:

A system manufactures molded fatty acid based material products by
forming a fatty acid based material paste and injecting the paste into a
mold having internal cavities. The system includes a controller that
regulates heat generated by a movable member in the barrel of an
injection molding machine and a cooling jacket on the exterior of the
barrel to enable nearly melted fatty acid material and nearly solid
melted fatty acid material to mix within the barrel to form a paste that
is ejected into a mold to form the products. The paste enables the
products to form a skin that is less susceptible to shrinkage during
cooling so the product is formed without voids that cause breakage or mar
aesthetic appearances of the product.

Claims:

1. A system for manufacturing molded food products comprising: a
volumetric container having a wall that encloses a space, the wall having
an inlet and an outlet, the inlet being configured to receive fatty acid
based material pieces that are solid at room temperature and feed the
material pieces into the container; a cooling member located within the
volumetric container that removes heat from the wall; a heated member
located within the volumetric container at a position separated from the
wall of the volumetric container, the heated member being configured to
heat the fatty acid based material within the volumetric container to a
first temperature that is less than a melting temperature of the fatty
acid based material to form a paste; an ejection member configured to
force a portion of the fatty acid based material paste from the
volumetric container through the outlet of the volumetric container; a
mold having at least two separable shells that form product cavities, the
mold being in fluid communication with the outlet of the volumetric
container to receive the fatty acid based material paste, the at least
two separable shells having gates that are sized to prevent elevation of
the fatty acid based material paste above the first temperature, and the
at least two separable shells having a temperature that enables the fatty
acid based material paste to form a skin upon contact with an internal
surface of one of the at least two separable shells; and a controller
coupled to the heated member, the cooling member, and the ejection
member, the controller being configured to keep the heated member in a
first temperature range that maintains fatty acid based material at the
first temperature proximate the heated member, to keep the cooling member
in a second temperature range that maintains fatty acid based material at
a second temperature proximate the cooling member, and to energize the
ejection member to form the fatty acid based material paste proximate the
outlet of the volumetric container and eject the portion of the fatty
acid based material paste from the volumetric container through the
outlet.

2. The system of claim 1 further comprising: a second cooling member
proximate the mold, the second cooling member being maintained at a
temperature that enables the fatty acid based material paste injected
into the mold to form the skin upon contact with the internal surface of
at least one shell of the at least two separable shells.

3. The system of claim 5 wherein at least one shell of the mold is
coupled to a stationary frame, and at least one other shell of the mold
is coupled to a movable frame; and the system further comprises: a second
actuator coupled to the movable frame; and the controller is operatively
connected to the second actuator and the controller being further
configured to energize the second actuator selectively to move the
movable frame and the at least one other shell of the mold into and out
of mating with the at least one shell of the mold to enable the at least
two shells of the mold to separate and release molded products from the
mold.

4. The system of claim 1 wherein the movable member is a screw extruder.

5. The system of claim 1 wherein the movable member is a ram injector.

6. A system for manufacturing fatty acid based material comprising: an
injection molding machine having a barrel with a wall surrounding an
internal cavity, the barrel having an outlet; a cooling jacket mounted on
an exterior of the barrel; a movable member located within the internal
cavity of the barrel; a heater located within the movable member; an
actuator coupled to the movable member; and a controller coupled to the
heater within the movable member, the cooling jacket, and the actuator,
the controller being configured to regulate the heater to maintain the
movable member within a temperature range in which liquid fatty acid
based material proximate the movable member remains in a liquid or near
liquid state, to operate the cooling jacket to maintain the wall of the
barrel in a temperature range in which fatty acid based material
proximate the wall of the barrel remains in a solid or near solid state,
and to energize the actuator to cause the movable member to mix the
liquid or near liquid fatty acid based material proximate the movable
member with the solid or near solid fatty acid based material proximate
the wall of the barrel to form a fatty acid based material paste.

7. The system of claim 6, the controller being further configured to
energize the actuator to move the movable member and eject fatty acid
based material paste through the outlet of the barrel.

8. The system of claim 6 further comprising: a mold having at least two
separable shells that form product cavities, the mold being in fluid
communication with the outlet of the barrel to receive the fatty acid
based material paste, the at least two separable shells having gates that
are sized to prevent elevation of the fatty acid based material paste
above the first temperature; and a second heat exchanger proximate the
mold to maintain the mold at a temperature that enables the fatty acid
based material paste injected into the mold to form a skin upon contact
with an internal surface of one of the at least two separable shells of
the mold.

9. The system of claim 8 wherein at least one shell of the mold is
coupled to a frame of the injection molding machine, and at least one
other shell of the mold is coupled to a movable frame; and the system
further comprises: a second actuator coupled to the movable frame; and
the controller being operatively connected to the second actuator and the
controller being further configured to energize the second actuator
selectively to move the movable frame and the at least one other shell of
the mold into and out of mating with the at least one shell of the mold
to enable the at least two shells of the mold to separate and release
molded products from the mold.

10. The system of claim 5 wherein the movable member is a screw extruder.

11. The system of claim 5 wherein the movable member is a ram injector.

Description:

CLAIM OF PRIORITY

[0001] This application is a divisional application of and claims priority
to U.S. patent application having Ser. No. 12/236,431, which was filed on
Sep. 23, 2008, and is entitled "System And Method For Manufacturing Fatty
Acid Based Material Products With An Injection Molding Process," and
which will issue as U.S. Pat. No. 8,246,891 on Aug. 21, 2012, and to U.S.
patent application having Ser. No. 12/235,174, which was filed on Sep.
22, 2008, and is entitled "System And Method For Manufacturing Fatty Acid
Based Material Products With An Injection Molding Process."

[0003] Molding materials with a base of fatty acid-like properties
produces mixed results. Most materials have a significant density
difference between their solid state and the liquid state typically
injected into molds. Chocolate products, for example, generally are
prepared industrially by conching a ground chocolate ingredient mixture
paste at a temperature of from about 50 degrees to about 85 degrees C.
and by tempering the conched chocolate to provide a fluid, pourable mass.
Viscosity considerations require that the fluid tempered chocolate
generally be directed immediately to a molding operation for final
product preparation. Although cooling can be carried out during
tempering, correct tempering procedures generally require that the
chocolate have a temperature on the order of from about 27 degrees C. to
about 35 degrees C., depending upon the chocolate composition and
character. In addition, when using tempered chocolate in a molding
operation, temperature control of the mold also is important, and in
general, heating and cooling operations are required.

[0004] If the mold temperature is less than the temperature of the
tempered fluid chocolate being injected into the mold, the chocolate
adjacent the mold surface tends to contract at a rate different from the
remainder of the chocolate in the mold which, in turn, tends to result in
rough product surfaces and/or de-molding problems and/or poor gloss. On
the other hand, if the mold is too hot, the chocolate may lose its temper
at least partially, which tends to result in poor contraction during
cooling and/or in producing a product having a poor surface-finish. Thus,
the molding operation generally requires heating a mold to a temperature
which substantially corresponds to that of the tempered fluid chocolate.

[0005] After filling the mold cavity, the mold is cooled to set the
chocolate. Generally, a cooling tunnel assembly or a multi-tier cooler,
as known in the art, are used for this cooling. A properly set and glossy
product typically requires cooling the mold and chocolate to a
temperature on the order of from 10 degrees C. to 20 degrees C. The rate
of cooling is also important, not only because of cooling contraction
considerations, but also because an at least initial gradual controlled
cooling should be employed so that the final product does not exhibit or
tend to develop, prematurely, fat bloom. Thus, a cooling cycle time on
the order of from about 20 minutes to about 30 minutes is typically
required for a properly set product. This time frame limits the amount of
production, while the equipment and energy necessary for thermal control
increases the expense of product manufacture. Numerous materials other
than chocolate, such as cheese, soaps, various candies and
confectionaries, as well as intermediate fabrication processes that use
wax of various forms, and the like, exhibit similar behaviors and have
similar process requirements.

SUMMARY

[0006] A method has been developed that enables fatty acid-like material
products, such as those made from chocolate, to be formed without
requiring the mold to be held at the temperature of the material being
injected into the mold and then being cooled thereafter. The method forms
a fatty acid based material paste and injects the fatty acid based
material paste into a mold having internal cavities that are cooled to a
temperature that is less than the fatty acid based material paste being
injected into the mold. The method includes generating a fatty acid based
material paste, cooling a mold having at least two separable shells that
form product cavities to a temperature that is less than the fatty acid
based material paste, injecting a portion of the fatty acid based
material paste under pressure into the mold, and separating the shells of
the mold to release products from the product cavities. The paste may be
formed by a variety of techniques, including heating a first quantity of
solid fatty acid based material particulates to a temperature at which
the fatty acid based material particulates reach a liquid state and then
mixing the first quantity of fatty acid based material particulates with
a second quantity of fatty acid based material particulates in or near a
solid state to form a paste. This paste is suitable for injection into a
mold that has been cooled to a temperature that is less than the fatty
acid based material paste.

[0007] This method of product manufacture may be used with an injection
molding machine to form a system for manufacturing molded food products.
The system includes an injection molding machine having a barrel in which
a heated member is located, the barrel having an outlet. The system also
includes a cooling jacket mounted on an exterior of the barrel, a movable
member located within the barrel, a heater located within the movable
member, an actuator coupled to the movable member, and a controller
coupled to the heater, the cooling jacket, and the actuator, the
controller being configured to regulate the heater to maintain the
movable member within a temperature range in which liquid fatty acid
based material remains in a liquid or near liquid state, to operate the
cooling jacket to maintain the barrel in a temperature range in which
fatty acid based material remains in a solid or near solid state, and to
energize the actuator to cause the movable member to mix the liquid or
near liquid fatty acid based material proximate the movable member with
the solid or near solid fatty acid based material proximate the barrel to
form a fatty acid based material paste.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The foregoing aspects and other features of a molded fatty acid
based material product manufacturing system and method are explained in
the following description, taken in connection with the accompanying
drawings.

[0009] FIG. 1 is a diagram of an injection molding machine in which molded
fatty acid based material products may be manufactured.

[0010]FIG. 2 is a flow diagram of a process that may be implemented by
configuring the controller of the machine in FIG. 1 to perform the
process.

[0011]FIG. 3 illustrates an alternative method for manufacturing the
paste that is injected into the mold of FIG. 1.

[0012]FIG. 4 illustrates another alternative method for manufacturing the
paste that is injected into the mold of FIG. 1.

DETAILED DESCRIPTION

[0013] FIG. 1 depicts an injection molding machine 10 in which the method
of manufacturing molded fatty acid based material products, which is
described below, may be implemented. The term fatty acid based material
is intended to include all fatty acid and similar materials known in the
various food, cosmetic, soap, and wax industries. This range of fatty
acid based materials is hereafter described with reference to a chocolate
or fatty acid food material for simplicity. The custom made injection
molding machine 10 has a barrel 12 with a diameter of 80 mm and a length
l of approximately 2.5 m. Solid food pieces, such as chocolate buttons,
bits, or pastilles, may be supplied to the injection-molding apparatus 10
through a feeder 18. As discussed in more detail below, the paste may be
generated elsewhere and then fed to the injection molding machine. If
solid food pieces are provided through the feeder 18, the food pieces may
be produced by any known technique. The size of the pieces can range from
more than 12 mm to about 1 microns. The small size of the pieces provides
greater surface area for heating to enable the pieces to respond to
heating and cooling quickly. While smaller pieces are desirable for this
reason, manufacture, storage, and transport of the pieces may influence
the optimal size for the food material used in a particular environment.

[0014] A temperature profile of the barrel 12 is maintained by one or more
cooling jackets 14, which are grouped into independently controlled zones
along the barrel 12, including along a barrel head 12a and a nozzle
portion 16. The cooling jackets include fluid passageways that enable a
coolant to flow through the jacket. The coolant absorbs heat from the
barrel and the warmed fluid is passed through a heat exchanger 44 to
remove the heat from the fluid. The fluid may then be re-circulated
through the jacket to continue the cooling of the barrel. The fluid may
be, for example, an oil or an ethylene glycol. A rotary actuator or drive
20 turns a retractable screw 22 within the barrel 12. The screw 22 is
also hollow to enable heaters (not shown) to be placed within the screw.
Selective activation of the heaters controls the temperature of the
screw. In one injection molding machine, the screw 22 has a diameter of
25 mm.

[0015] The heaters or other thermal controlling elements within the screw
22 and the cooling jackets 14 are coupled to a controller 30. The
controller is a processor and related input/output circuitry with
volatile and non-volatile memory. Programmed instructions are stored in a
portion of the memory for execution by the processor to control the
injection molding process. These instructions may be programmed in a
known manner to configure the controller to monitor the temperature of
the barrel, the screw, and other areas of the machine and to regulate
these temperatures by controlling the heaters within the screw and the
flow of coolant through the cooling jackets. Additionally, the controller
is coupled to the drive 20 to move the screw within the barrel 12 in a
programmed manner. Thus, the ability of the machine 10 to form solid
products depends upon the configuration of the controller by the
programming instructions stored in the memory of the controller. In one
envisioned application for food products, the nominal target temperature
is in a range of about 27 degrees C. to about 95 degrees C. for the screw
and the nominal target temperature is in a range of about 15 degrees C.
to about 25 degrees C. for the barrel.

[0016] If all of the food pieces within the barrel reach the melting
temperature for the food being processed, the fatty food fails to respond
to the rotation of the screw to move forward to the nozzle 16 of the
barrel 12. On the other hand, if all of the food pieces remain in a solid
state, the fatty food fails to achieve sufficient flow characteristics to
enable injection of the material from the barrel into a mold coupled to
the nozzle 16. To enable the food to acquire a consistency that enables
movement within the barrel and injection into the mold, the controller
has been configured through programming instructions to heat the screw to
a temperature that maintains the food pieces proximate the heated member
in a liquid state and to regulate the barrel temperature at a level that
keeps the food pieces proximate the barrel in a solid state. The liquid
food proximate the screw enables the screw to rotate freely. The screw
rotation acts to mix the melted fatty food with the solid fatty food
between the screw and the barrel to form a paste. The paste also responds
to the rotation of the screw by being moved forward towards the nozzle. A
non-return valve 36 prevents the paste from squeezing backwards into the
barrel portion 12 during injection. Thus, the controller maintains the
screw 22 at a temperature that generates a sufficient amount of melted
fatty food to form a paste when mixed with the solid fatty food in the
barrel by the rotation of the screw.

[0017] As used herein, the term "paste" refers to a material in a state
between liquid and solid, which may be described as semi-liquid or
semi-solid. These two descriptions, semi-liquid and semi-solid, are
synonymous. The liquid state for the material being processed is a state
in which the material is pourable and conforms to the shape of a sharp
cornered container as the material is poured into the container. The
solid state refers to the state in which the material retains a given
three dimensional shape having a non-supported square cross-section
projection with a length/width ratio of 5 for a time period of 24 hours
under uniform environmental conditions. This description can apply to
"flaccid" materials, such as cheese, where the initial shape may include
droop, but does not increase its droop under the conditions stated above.
The width referenced is the widest cross-section acting to resist droop
due to gravity and would be uniform over the length of cross-section.
Some fatty acid based materials over some portion of the temperature
range at which the described paste state exists may also be described as
a slurry since a portion of the paste is liquid and another portion of
the paste is solid or nearly solid. The reader should appreciate that the
waxy nature of such material may undergo a state change from solid to
liquid over a wide temperature range that is extended in comparison to
other more familiar substances, such as water becoming ice when chilled,
steam when heated, or solder transitioning from a nominally malleable
solid state to liquid almost immediately after supplying sufficient heat.
Different constituents in the fatty food melt at different temperatures
so the material is not easily induced into a homogeneous paste state by
simply altering its temperature. Therefore, fatty acid food and other
fatty acid based materials may appear to be solid when nearly so and
liquid when not fully so.

[0018] This understanding of material states related to temperature should
aid the reader in seeing that churning or mixing fatty food that is
liquid with fatty food that is solid results in a temperature change of
that fatty food mixture and yield a more uniform paste consistency over a
fairly short period of time. The process of producing this paste state
can occur by mixing fully liquid material with fully solid material in
appropriate proportions based on churning or mixing effectiveness for an
adequate time, allowing the cooler mass to warm and the warmer mass to
cool. A paste state may also be attained by mixing fatty food that has
not fully reached the liquid state with fatty food that is not fully
solid, to generate any combination of fully or partially liquid fatty
food mixed with fully or nearly fatty food, depending upon the amount of
time the two states or near-states are mixed and the effectiveness of the
mixing. The mixing or churning of the range of material states is
affected by shear tendencies of the different states and these tendencies
are affected by temperature and mass of the different material states
confined between heated and cooled members or structures of the injection
molding machine or press. Holding material at a temperature intermediate
the solid and liquid states for an extended period of time may allow the
material to become a usable paste, but this method of producing paste may
not be practical in high volume production scenarios.

[0019] The press barrel 12 is maintained at a temperature that prevents
all of the solid fatty food in the barrel from being melted so a paste
can be formed. Although the barrel may be described as cooled, this term
is used in a relative sense. Thus, the "cooler" temperature of the barrel
is defined as being below the fatty food melt temperature so this surface
may in fact, at times, be heated and, at other times, be cooled to
prevent it from becoming too hot. The rotation of the screw 22 also
mechanically transports the paste to the nozzle 16 so the controller can
energize the reciprocating actuator and pressurize a portion of the paste
to eject a shot of paste from the nozzle 16 into the mold 24. Once the
paste shot has been injected, the rotary drive 20 rotates the screw 22 to
continue making the paste and to transport a portion of the paste forward
to the nozzle. The rotary drive portion 20 is controlled by the
controller to transport each shot through the barrel portion 12 in
regular cycles at a set velocity to enable the time that each shot spends
in the different temperature zones of the barrel 12 to be precisely
controlled. This precision enables the consistency of each shot to be
reproducibly controlled. A drive or actuator may rotate a screw for
mixing and/or feeding fatty food paste or may accomplish those functions
with a linear motion, such as reciprocating motion of a screw or a
piston, plunger, or ram. Combinations of rotary and linear motion may be
used with a screw or ram within a molding machine. An actuator may also
move an ejection member that is independent of the barrel and an internal
feed device or conveyor, which may be a ram, screw, or some conveyor
combination.

[0020] The mold 24 is a mold having internal cavities that are coupled
together by runners, as known in the art, although other types of molds
may be used. As shown in FIG. 1, a clamp 40 moves the two sections 24a,
24b of the mold 24 towards and away from one another. The applied clamp
force is dependent on the size and the number of the products to be
molded. In one envisioned embodiment, a clamp force of about 25 tons is
applied to the mold. The mold also includes an inlet that is configured
for mating with the nozzle 16 of the barrel 12. The inlet enables a paste
shot ejected from the nozzle to enter the mold to form items within the
internal cavities of the mold.

[0021] The fatty acid based material paste enters the mold cavities
through gates that are fed either by the nozzle of the barrel or, if
multiple cavities are within a mold, runners extending from the nozzle.
Because the fatty acid based material paste is thicker than materials
typically injected into molds and a goal of the process is to prevent
fatty acid based material temperatures from elevating excessively, larger
than typical gates are desired. Small gates require higher injection
forces that increase the velocity and friction of the material as it
enters the cavity. These factors heat the material and may attenuate the
benefit of injecting fatty acid based material paste into a mold with a
paste consistency. Gate size is influenced by the timing of the injection
cycle and the volume and shape of the cavity or cavities to be filled. In
one envisioned embodiment, the gate size has a diameter of approximately
5 mm.

[0022] The mold 24 also includes one or more fluid passageways that are
not in fluid communication with the internal cavities. These passageways
may be coupled to a cooling system that pumps a coolant through the
passageways to remove heat from the mold. The coolant may be an oil or
ethylene glycol and the coolant is circulated through a heat exchanger 44
to remove heat from the coolant and renew the ability of the coolant to
maintain the temperature of the mold below the liquid state maintaining
temperature. Thus, a paste shot entering the mold forms a skin as a
portion of the shot contacts a wall of an internal cavity of the mold.
The skin helps seal the fatty acid based material product so it is
relatively impervious to moisture after the fatty acid based material
product is released from the mold. Additionally, the skin is sufficiently
thick that the mold may be separated by the controller operating the
clamp relatively quickly after the injection of the paste shot into the
mold without deformation of the fatty acid based material product. The
skin and the amount of paste in a shot are adequate to enable the fatty
acid based material internal to the skin to cool without shrinkage or
breakage of the skin. In one envisioned embodiment, the mold is
maintained within a temperature range of about -5 degrees C. to about 5
degrees C. Depending upon material properties and mold dwell times, this
temperature range may extend from about -60 degrees C. to over 20 degrees
C. Because moisture in the air may produce ice particles at the lower
temperatures, the process is better performed in a relatively dry
environment.

[0023] A method 100 that may be implemented by programmed instructions
executed by the controller is shown in FIG. 2. In general, the method
generate a paste from solid fatty acid based material, injects a portion
of the paste under pressure into a cooled mold having at least two
separable shells that form product cavities, and separates the shells of
the mold to release molded fatty acid based material products from the
product cavities. The injection pressure used in one application was
nominally about 5 Bar during the initial and mid-phase of fill and was
increased to about 40 Bar to ensure the mold was fully packed at the end
of the fill cycle. In one envisioned embodiment, solid fatty food pieces
are loaded from a source, such as a hopper of an injection molding
machine, into the barrel of the machine (block 104). In other possible
embodiments, the fatty acid based material may be melted to form a liquid
state. This liquid fatty acid based material may be fed into the
injection molding machine. In the injection molding machine, the screw of
the machine is heated to a temperature within a range that converts solid
fatty acid based material to a liquid or near liquid state or that
maintains that state (block 108). Additionally, the wall of the barrel is
regulated to a temperature within a range that converts liquid fatty acid
based material to a solid or maintains solid fatty acid based material in
a solid state (block 110). The screw is rotated to mix the melted fatty
food proximate the screw with the solid fatty food proximate the barrel
(block 114). The mixing of the melted fatty food and the solid fatty food
forms a paste that is transported by the rotating screw to the nozzle of
the barrel (block 118). The screw is then retracted to enable a portion
of the shot to enter the nozzle (block 124) and then the screw is driven
forward to eject a shot of the paste from the nozzle of the barrel (block
128). The shot enters a mold that is cooled to a temperature that enables
a portion of the shot that contacts the walls of the internal cavities to
form a skin for a food product (block 132). The mold is separated (block
136) to enable the food products to fall from the mold. The mold is then
closed (block 140) and the process continues (block 104).

[0024] The injection molding machine and method of operation described
above requires an injection molding machine to heat and to cool the
material within the barrel of the injection molding machine. The cooling
is performed by circulating a heat absorbing medium about the barrel to
enable the barrel to be maintained in a temperature range that causes the
material to exist in a solid state proximate the barrel. The heating is
performed by circulating a heated media in the interior of a hollow
screw, operating a cartridge heater within the screw, or by regulating
current flow in a resistive heater associated with the screw. By
providing material in both a solid state and a liquid state within the
injection molding machine, a paste can be formed having a consistency
that enables the screw to transport the paste forward to an outlet and
eject the paste into a cooled mold. The temperature of the mold enables
the paste to flow through the gates and passageways of the mold and, upon
contact with a wall of an internal cavity, form a skin. This skin
provides an exterior for the product with relatively few surface defects.
The skin also enables the remaining paste to fill the interior of the
skin without voids while maintaining desirable aesthetics. Upon release
of the product from the mold, the skin is sufficiently solid that little
or no breakage occurs in the ensuing handling or occasional mishandling
and the continued cooling is sufficiently uniform that dimples, cracks,
and other defects are less likely to form than with other previously
known mold methods for ink stick formation.

[0025] The injection molding machine and method described above may be
used to form solid objects from fatty acid based material materials that
are capable of being both liquid and solid. For example, chocolate,
taffy-like candies, and cheese can be melted to form a liquid and cooled
to form a solid. Consequently, such fatty acid based material products
may be fed to an injection molding machine as either a liquid or a solid
and treated by the screw and barrel to form a fatty acid based material
paste. This paste may then be transported by the screw to the ejection
port and shot into a cooled mold for formation of a solid object, such as
a chocolate bar or cheese block. Other products, for example, candle wax,
soaps, and cosmetics, may also be molded with this method.

[0026] In another envisioned embodiment of the injection molding machine
useful for manufacturing fatty acid based material objects, the paste may
be produced outside of the injection molding machine. The paste may be
made, for example, by mixing a predetermined quantity of the material in
a solid state with a predetermined quantity of the material in the liquid
state to form the paste. The paste may then be pumped or gravity fed into
the injection molding machine. The barrel and screw of the injection
molding machine are regulated by the controller to remain within a
temperature range that keeps liquid material proximate the screw and
solid material proximate the barrel. The paste material is transported to
the ejection port and shot into the cooled mold as described before.

[0027] Other methods may be used to obtained material pastes. For example,
the described material paste consistency can be attained by a method in
which a large mass of material is held in a volumetric container, such as
container 304 shown in FIG. 3, which is placed in a heating chamber 308,
such as an oven. A controller 312 is coupled to temperature sensors (not
shown) in the heating chamber so the controller can regulate the chamber
temperature at an appropriate temperature for a sufficient time to obtain
uniformity in the paste without melting material in the container. FIG. 4
illustrates another example in which solidified material is forced into
inlet 404 of a barrel 400 and urged through constricting passages 408 and
412. The passages are brought to elevated temperatures by a heating
element 416 to heat the material. The convergence of the materials before
exiting through the outlet 420 mixes the heated flows for formation of
the paste. Again, heating element 416 may be coupled to a controller for
regulation of the temperature of the passageways.

[0028] It will be appreciated that various of the above-disclosed and
other features, and functions, or alternatives thereof, may be desirably
combined into many other different systems or applications. Various
presently unforeseen or unanticipated alternatives, modifications,
variations, or improvements therein may be subsequently made by those
skilled in the art, which are also intended to be encompassed by the
following claims.

Patent applications by Edward Francis Burress, West Linn, OR US

Patent applications by Terry Alan Smith, Aurora, OR US

Patent applications by XEROX CORPORATION

Patent applications in class Of mold cavity or fluent material to shaping or discharging orifice

Patent applications in all subclasses Of mold cavity or fluent material to shaping or discharging orifice